APPLICANT'S ABSTRACT: Significant problems can result from the concomitant use of prescription drugs with alcohol. Alcohol-drug interactions are important for elderly drinkers - even moderate drinkers - because of the likelihood of polypharmacy, aging-related changes in pharmacoknetics and pharmacodynamics, and aged-linked changes in health. There are no studies known that have examined, prospectively, the health outcomes of common patterns of concomitant use of alcohol and alcohol-interactive drugs by the elderly. Especially needed are prospective studies that examine the impact of joint use of alcohol and prescription drugs that are commonly used by the elderly. We propose to take advantage of an existing data base that provides extensive information on alcohol use and alcohol-interactive drug use by the elderly. Samples of elderly with known use of prescription drugs and alcohol-interactive prescription drugs were obtained from members of the Pennsylvania Pharmaceutical Assistance Contract for the Elderly (PACE). PACE claims data were used to develop random samples of users of nine different pharmacologic-therapeutic classes of drugs. Cross-sectional telephone and mail surveys on alcohol use and health and functional status were obtained from over 10,000 PACE elderly users of prescription drugs in 1990 and 1991. We propose to conduct a historical prospective study covering the period 1989-1995, involving linkage of PACE claims data, mortality data, alcohol related survey data, and Medicare claims-based health care utilization data. The specific aims of the proposed study are to assess the impact of use of alcohol, prescription drugs, and alcohol-drug interaction on mortality, selected clinical outcomes, and on health-care expenditures as measured by Medicare and PACE claims-based health services.